check_dma_on_stack.c

   1 /*
   2  * Copyright (C) 2009 Dan Carpenter.
   3  *
   4  * This program is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU General Public License
   6  * as published by the Free Software Foundation; either version 2
   7  * of the License, or (at your option) any later version.
   8  *
   9  * This program is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12  * GNU General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU General Public License
  15  * along with this program; if not, see http://www.gnu.org/copyleft/gpl.txt
  16  */
  17
  18 #include "smatch.h"
  19
  20 static int my_id;
  21
  22 static void match_dma_func(const char *fn, struct expression *expr, void *param)
  23 {
  24         struct expression *arg;
  25         struct symbol *sym;
  26         char *name;
  27
  28         arg = get_argument_from_call_expr(expr->args, PTR_INT(param));
  29         arg = strip_expr(arg);
  30         if (!arg)
  31                 return;
  32         if (arg->type == EXPR_PREOP && arg->op == '&') {
  33                 if (arg->unop->type != EXPR_SYMBOL)
  34                         return;
  35                 name = expr_to_str(arg);
  36                 sm_error("doing dma on the stack (%s)", name);
  37                 free_string(name);
  38                 return;
  39         }
  40         if (arg->type != EXPR_SYMBOL)
  41                 return;
  42         sym = get_type(arg);
  43         if (!sym || sym->type != SYM_ARRAY)
  44                 return;
  45         if (get_param_num(arg) >= 0)
  46                 return;
  47         name = expr_to_var(arg);
  48         sm_error("doing dma on the stack (%s)", name);
  49         free_string(name);
  50 }
  51
  52 static void register_funcs_from_file(void)
  53 {
  54         struct token *token;
  55         const char *func;
  56         int arg;
  57
  58         token = get_tokens_file("kernel.dma_funcs");
  59         if (!token)
  60                 return;
  61         if (token_type(token) != TOKEN_STREAMBEGIN)
  62                 return;
  63         token = token->next;
  64         while (token_type(token) != TOKEN_STREAMEND) {
  65                 if (token_type(token) != TOKEN_IDENT)
  66                         return;
  67                 func = show_ident(token->ident);
  68                 token = token->next;
  69                 if (token_type(token) != TOKEN_NUMBER)
  70                         return;
  71                 arg = atoi(token->number);
  72                 add_function_hook(func, &match_dma_func, INT_PTR(arg));
  73                 token = token->next;
  74         }
  75         clear_token_alloc();
  76 }
  77
  78 void check_dma_on_stack(int id)
  79 {
  80         if (option_project != PROJ_KERNEL)
  81                 return;
  82         my_id = id;
  83         register_funcs_from_file();
  84 }